Once you have a proper HKL format file you may wish to segregate it
into a test and working set. The command hkl_segregate performs
that task. If you issue the command giving only the name of you HKL file
two new files will be created, one containing 10% of the data and the other
containing the rest. The second argument can be used to name a test set
that you want to match. When refining a crystal which is isomorphous to
some previous project you will want to use the same reflections in the
new test as as the old.